<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    // 利用generator 封装 interator

    function * fn  (arr) {
        for(var i = 0; i < arr.length; i++) {
            yield arr[i];
        }
        return;
    }
    var arr = [1,2,3,4,5,6,7,8]
    
    var obj = fn(arr);
    console.log(obj);
    for(var val of obj) {
        console.log(val);
    }
    
</script>
</html>